When my father told me he was dating someone and wanted me to meet her, I was relieved.

My dad's love life was fairly peripheral to my childhood. His job took him away from home, and he kept small flats wherever he was working that year. His love life stayed with his work life, and my childhood home was where he would always be, ready to be a dad, for the two weekends out of three he spent with my brother and me.

There was a string of casual relationships we were never supposed to know about. Clues were left at his house or his temporary flats when we visited — a hat, a scarf, a lipstick that had rolled behind the toilet. But after one bad reaction to an early girlfriend, he never introduced anyone to us. He never even mentioned them.

So once I was an adult and my dad told me he wanted me to meet someone, I was old enough to realize how unhappy he had been. I wanted him to be happy. I wanted this to go well. I wanted very badly to like her.

And at first, everything was picture-perfect. She was smart, funny, easy to talk to, and my dad adored her.

Two months later, my dad revealed that they were engaged. I was shocked that it seemed so soon, but I was happy. He could have the family he always wanted with her and her son, the traditional family unit he'd missed out on when my brother and I were teenagers. He was smiling and happy, holding her hand and walking around with the kind of blind grin on his face that I hadn’t seen in years.

Just looking at how lovestruck he was made me emotional. I was overcome by tears and went to the bathroom to compose myself. He misread this and came to find me on my way back; he told me that if my brother and I were not totally OK with this, it wouldn't happen.

I told him not to be a bloody idiot and that I was ridiculously happy for him.

I got to know his fiancée (who I'll call Alice) and grew to like her for her forthrightness, know-how and caring for my father. The way they teased each other was adorable. She was younger than him and poked fun at him for his music choices. She cooked healthy food for him to help him with his diabetes. She got him involved in fun activities with her son, birthday parties and trips out where he could be the loving father he was to us when we were little. She brought out the best in him. He was always smiling whenever I saw him. He was always happy.

After the wedding was when I started to feel doubt. I was staying with my mother for the holidays and came downstairs to find her sobbing over an email from my father telling her to cut off contact with his parents and his family, and accusing her of holding back money from my brother and me while he gave us everything.

I was shocked. My parents had maintained an amiable separation for nine years at that point. My mother still exchanged Christmas cards with his parents. As for money, my mother was all but bankrupt, but she didn't take anything from my father when she left him — no alimony, no pension, no house, no assets, nothing. Dad paid mum child support, but it was voluntary; he'd offered it, and he'd been paying that directly to myself and my brother as an allowance since we were 16 so we could buy our own clothes, shoes, lunches and so on, teaching us the value of money.

Why was this happening now?

I asked to read the email and I smelled a rat. My father was dyslexic. Even if he had put this email together, someone else, someone with access to his email account, had helped him write it.

I comforted my mother and gave Alice the benefit of the doubt. It was natural for Alice to feel uncomfortable with my mother's continued relationship with my father's family, I thought. She didn't know my mother and her financial situation, and dad had a new family to support now. I was an adult, so perhaps I should rely less on him for financial support.

So I asked my father to talk to me about my finances rather than my mother and suggested that he stop helping support me. He did, my mother sent dad's parents a “Dear John” letter of sorts, and life continued.

Shortly afterwards, my dad accused my brother of being a coke addict, cut him off (he had offered to help pay my brother's rent while he was studying), and left him with a choice between rent money and food money. My brother worked, but a part-time job wouldn't cover his room's rent.

Alice had made the initial accusation. She was an ex-addict and apparently she knew the signs. My brother was too thin, she said — too pale. He avoided questions about his life and friends. They had found weed in his room as a teenager — a short step to harder drugs, she argued. She felt that the best thing for my dad to do was to stop enabling my brother.

Soon, my brother was bin-diving for food. Before he came home for the holidays and we could feed him properly he, at over six feet tall, weighed only nine stone (about 125 pounds). He had always been thin, but now he was skeletal.

Alice took his unhealthy appearance as proof that she was right and told my father so. His relationship with my brother drew strained to the point of not speaking.

Again, I gave her the benefit of the doubt.

I was furious, but with my father for believing this of my brother — not at Alice for suggesting it. She was so nice to us! She was clearly just trying to help. I had just left to study abroad and was only hearing one account. Surely she genuinely thought that my brother was an addict; it was no secret that he was no angel. His relationship with my dad had always been up and down.

Dad hadn't called or replied to my emails while I was living abroad, but he was busy with his new family. Then I found out through my brother that apparently he and his new family were busy moving.

They had moved and sold my childhood home while I was away and they hadn't even told me. Neither of us had the new address until months after.

Again, benefit of the doubt.

Moving is stressful. It just slipped their minds to tell me. And surely my childhood home was not convenient for Alice; she had friends closer to London and dad had work there, so it only made sense to move; a fresh start for them where Alice could have her own family set up. It hurt, but it was normal for her to want to establish her own family home.

Meanwhile, my brother told me that he thought there was something wrong with our dad, that he wasn't thinking straight, just stonewalling my brother's explanations as he tried to show my dad his bank account and how he simply couldn't afford food, let alone a coke habit. Dad had always been rational, he said, he had always listened, but now didn't seem to understand what was being said. They had a screaming row where my brother yelled at him to get his head checked out because something was clearly wrong.

I thought my brother was exaggerating because he was angry. Turns out, he was the only one of us that saw the signs.

Three months later, my father collapsed on a family holiday in Spain with Alice and her son, and was rushed to hospital. He had major brain surgery to remove as much of a tumor as possible. I was contacted while still studying abroad, and Alice assured me she would get me home to see my father, who was in critical condition.

I waited on the other side of the world for days before I gave up on Alice's help and took my maternal uncle up on an offer to pay for my flight home — a flight I didn't have the money in my account to pay for, having booked my return for months later in advance.

But then dad wasn't just my dad, he was Alice's husband. Someone she loved was at death's door; I couldn't expect her to think of me at a time like this. I mustn't be selfish; I must think of how badly this must be affecting her too. The important thing was to get home.

I got to see him a week after he collapsed. He was awake to talk to me, although I was told he was too weak for me to spend much time with him. I left with Alice still at his side, the devoted wife. I was glad she was there to advocate for and take care of him, especially as he could no longer remember the names of his diabetes medication and needed someone to remind doctors what he could take, what he was allergic to, and to monitor his sugar levels.

For a long time, my brother was forbidden to see him. Alice would badmouth him in front of me and my father, and I would try to mediate, to say how badly my brother just wanted to be with him.

Dad relented just before he was diagnosed as terminal.

My brother and I sat outside the hospital on a bench with him as he chain-smoked and to be strong for him as tears slid down his face.

“Please do not smoke on hospital grounds” cried the tannoy. My dad stuck his middle finger up at the security camera.

"I'm dying, you arseholes! I'll smoke as much as I fucking want."

My brother suggested climbing onto the roof and ripping the tannoy out, and my father gave a wry half grin and a huff, stubbing out his last cigarette. We went back in together, one of us holding each of his hands, to find Alice.

Alice was my father's primary carer. It was hard for her. She started drinking more. Sometimes she would call my brother or me hungover and ask us to meet dad for his hospital appointments because she wasn't OK to drive. She asked that we both visit their home only one afternoon a week to keep the pressure off her. My brother and I offered to help with dad's care, but were turned down. When we visited, we would cook, clean, shop, anything to help out. And Alice would break down and scream at us that we weren't doing enough.

Being a carer is stressful, and she was losing her husband; it wasn't surprising that she was resentful. I could do more.

Dad started to spend a few days at a time in a hospice to give her some relief from care. At first, my brother and I would take this opportunity to see more of him and visit when Alice wouldn't need to worry about catering for us. But after a while, we stopped being told when he was in a hospice. Alice would tell us she forgot, and again, I gave her the benefit of the doubt, assuming that the stress of caring for my father and her grief over losing him meant that telling me his schedule was not her priority.

She started badmouthing my relatives when I came over to see dad at their home, saying they weren't supportive, that they didn't like her, that they needed to understand her struggles more.

Excuses were made for why I wasn't allowed to visit my father on my one day a week. He wasn’t up to it, he was ill, he was tired. I believed her. I mustn't put my father under pressure, I mustn't make him stressed. I kept telling myself, it's more important that he gets enough rest than it is for me to see him. His health is more important than spending time with him.

When she told me she'd forgotten to tell me about a hospice visit, I made an effort to believe her. But these slips of memory continued, and my doubts kept resurfacing.

My doubts solidified when my brother came to have dinner with my mother and I; he said that he wasn't able to visit my father in the hospice this week and asked if I could I go instead. Alice had told me on the phone that very day that yes, my father was at a hospice but that he was too weak to have visitors and just wanted to sleep. My brother, however, said he was sure it would be fine.

I called the hospice. Was my father well enough to have visitors?

Oh yes, he was fine for visitors, they said, so long as they were family.

His approved visitors list had been given to them by his wife and she, his brother and his two sons were on it, the hospice told me. I asked if it was OK for me, his daughter, to visit, and was met with “He has a daughter?”

Alice responded to my second call with her that day with the opinion that my father was in too delicate a condition to have stress in his life. Apparently, I qualified as stress. If I disagreed with her in front of my father, questioned her decisions or integrity, or referred to her negatively in any way, she would take steps to prevent me seeing him altogether.

Suddenly, I viewed my dad's refusal to see my brother for months with new eyes. Dad had never told me that he didn't want to see my brother. Alice had told me my dad didn't want to see him.

I played along, I kept my mouth shut, tried not to rock the boat, tried to keep what was going on from my father — partly through fear of her carrying out her threat, partly because she was right that the last thing my father needed was stress. What good could me confronting her or telling my father do other than cause him grief? What was more important: that I get to see my dad more often and show him his wife's true colours, or that he felt loved and cared for until he died?

I went with the latter. But it was hard.

I would be told by my brother that when Alice “forgot” to tell me my dad was in a hospice or cancelled my days with him with the same lies, Alice would tell my father I was “too busy” to see him. It was heartbreaking.

I last saw him a few days before he died. I had a few minutes alone with him before Alice came up and shooed me away. I helped him sit up and we hugged each other. He told me that he loved me; it was hard for him to get the words out, to remember what they were. But I heard him say “I love you.”

I tried to say it back, but I was crying. I choked on the “I” and squeezed his hand as I held him up because he couldn’t do it himself. Alice walked in and she stared at me, and I choked up completely. I couldn't say it in front of her. My jaw was cramping up with emotion, and I was almost hacking trying to get the words out and trying not to cry, because I couldn't cry in front of her.

I didn't tell him I loved him back, and he died a few days later. I will feel guilty about that for the rest of my life.

I won't go into detail about Alice's behaviour after dad died (although there's enough there for a whole other article). I will say that Alice began openly flaunting her true colours when she no longer had to keep up appearances in front of my dad. Dad left money for my brother and me in trust; she took it. He'd asked her to respect his memory; she started up with a new man a few months after he died. I'd asked to be left alone to grieve; she stalked me on social media and threatened my friend's child.

In a way, it was a good thing. All the doubts I'd had, all of the worries about seeing things from her point of view, that maybe I was in the wrong, that maybe this situation was my fault — they were appeased. This was not my fault. She was exactly the person I'd suspected her of being.

It's over five years later and she's emailed my brother “extending an olive branch” to our family. But apologies won't give me back time with my father or make the lies that she told him unheard.